Removal of chromate CrO 4 2− from water was investigated using nanofiltration as a possible alter... more Removal of chromate CrO 4 2− from water was investigated using nanofiltration as a possible alternative to the conventional methods of CrVI removal from aqueous solution. Retention measurements with single reference salt revealed that Donnan exclusion plays an important role. The ...
Micellar-enhanced ultrafiltration (MEUF) represents a potentially attractive tool for the removal... more Micellar-enhanced ultrafiltration (MEUF) represents a potentially attractive tool for the removal of different contaminants from wastewater. In this study, MEUF was carried out to investigate the retention of Eriochrome Blue Black R (EBBR), an anionic dye, from aqueous stream. N-Alkyltrimethylammonium bromide i.e. dodecyltrimethylammonium bromide (C(12)TAB), tetradecyltrimethylammonium bromide (C(14)TAB), cetyl-trimethylammonium bromide (C(16)TAB) and octadecyltrimethylammonium bromide (C(18)TAB) were taken as cationic surfactants, and NaCl, Na(2)SO(4), Na(2)HPO(4) as electrolytes. A hydrophilic membrane made of cellulose (molecular weight cut-off 10000 Da) was used in a cross-flow ultrafiltration unit. The removal of EBBR was studied as a function of dye and surfactant concentrations, ionic strength, transmembrane pressure and pH. The MEUF experiments showed that the highest dye rejection was about 99% for the used range of dye and surfactant concentrations. This retention depended slightly on dye and surfactant concentrations, ionic strength, pH and transmembrane pressure. However, permeate flux changed significantly with those parameters due mainly to concentration polarisation and osmotic pressure.
Journal De Chimie Physique Et De Physico-chimie Biologique, 1998
Measurements of superficial tension of n-alkyltrimethylammonium bromides in air/water-orthophosph... more Measurements of superficial tension of n-alkyltrimethylammonium bromides in air/water-orthophosphoric acid interface have been made by “stripping method". Data were evaluated by approximation to the Von Szyszkowski equation. Thermodynamic parameters as (Γmax, F, A, B, Δ G^circ_A, Δ GM and CMC) at different concentrations of orhophosphoric acid (0 at 3 M) are calculted. The CMC values of the homologous series in relation to the chain length were determined. They showed a good correlation with the Klevens equation. A minimum of CMC and (-ΔGM) was observed for the n-octadecyltrimethylammonium bromide, which has been attributed to the cosolvant effect and the change of medium properties. L'adsorption, de bromure de n-alkyltriméthylammonium à l'interface air/eau-acide orthophosphorique, a été étudiée par la mesure de tension superficielle en fonction du nombre d'atomes de carbone du groupement alkyle et de la concentration en acide orthophosphorique (0 à 3 M). L'analyse des résultats a été effectuée à l'aide de l'équation de Von Szyszkowski. Les grandeurs et paramètres thermodynamiques (Γmax, F, A, B, Δ G^circ_A, Δ GM and CMC) ont été déterminés et discutés selon l'équilibre de forces de répulsion électrostatique entre les têtes polaires et d'attraction hydrophobe des chaînes aliphatiques. Les valeurs des CMC obéissent à l'équation de Klevens. Dans le cas du bromure de n-octadécyltriméthylammonium les valeurs de la CMC et de (-ΔGM) présentent un minimum, attribué au changement des propriétés du binaire eau-acide orthophosphorique.
Removal of chromate CrO 4 2− from water was investigated using nanofiltration as a possible alter... more Removal of chromate CrO 4 2− from water was investigated using nanofiltration as a possible alternative to the conventional methods of CrVI removal from aqueous solution. Retention measurements with single reference salt revealed that Donnan exclusion plays an important role. The ...
Micellar-enhanced ultrafiltration (MEUF) represents a potentially attractive tool for the removal... more Micellar-enhanced ultrafiltration (MEUF) represents a potentially attractive tool for the removal of different contaminants from wastewater. In this study, MEUF was carried out to investigate the retention of Eriochrome Blue Black R (EBBR), an anionic dye, from aqueous stream. N-Alkyltrimethylammonium bromide i.e. dodecyltrimethylammonium bromide (C(12)TAB), tetradecyltrimethylammonium bromide (C(14)TAB), cetyl-trimethylammonium bromide (C(16)TAB) and octadecyltrimethylammonium bromide (C(18)TAB) were taken as cationic surfactants, and NaCl, Na(2)SO(4), Na(2)HPO(4) as electrolytes. A hydrophilic membrane made of cellulose (molecular weight cut-off 10000 Da) was used in a cross-flow ultrafiltration unit. The removal of EBBR was studied as a function of dye and surfactant concentrations, ionic strength, transmembrane pressure and pH. The MEUF experiments showed that the highest dye rejection was about 99% for the used range of dye and surfactant concentrations. This retention depended slightly on dye and surfactant concentrations, ionic strength, pH and transmembrane pressure. However, permeate flux changed significantly with those parameters due mainly to concentration polarisation and osmotic pressure.
Journal De Chimie Physique Et De Physico-chimie Biologique, 1998
Measurements of superficial tension of n-alkyltrimethylammonium bromides in air/water-orthophosph... more Measurements of superficial tension of n-alkyltrimethylammonium bromides in air/water-orthophosphoric acid interface have been made by “stripping method". Data were evaluated by approximation to the Von Szyszkowski equation. Thermodynamic parameters as (Γmax, F, A, B, Δ G^circ_A, Δ GM and CMC) at different concentrations of orhophosphoric acid (0 at 3 M) are calculted. The CMC values of the homologous series in relation to the chain length were determined. They showed a good correlation with the Klevens equation. A minimum of CMC and (-ΔGM) was observed for the n-octadecyltrimethylammonium bromide, which has been attributed to the cosolvant effect and the change of medium properties. L'adsorption, de bromure de n-alkyltriméthylammonium à l'interface air/eau-acide orthophosphorique, a été étudiée par la mesure de tension superficielle en fonction du nombre d'atomes de carbone du groupement alkyle et de la concentration en acide orthophosphorique (0 à 3 M). L'analyse des résultats a été effectuée à l'aide de l'équation de Von Szyszkowski. Les grandeurs et paramètres thermodynamiques (Γmax, F, A, B, Δ G^circ_A, Δ GM and CMC) ont été déterminés et discutés selon l'équilibre de forces de répulsion électrostatique entre les têtes polaires et d'attraction hydrophobe des chaînes aliphatiques. Les valeurs des CMC obéissent à l'équation de Klevens. Dans le cas du bromure de n-octadécyltriméthylammonium les valeurs de la CMC et de (-ΔGM) présentent un minimum, attribué au changement des propriétés du binaire eau-acide orthophosphorique.
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